Portal - Mac

Game Description:A unique take on puzzle gameplay by the makers of Half-Life. Portal is a new type of single player game that changes how players approach, manipulate, and surmise the possibilities in a given environment in a manner similar to how the Gravity Gun changed our approach to how an object may be leveraged in any given situation.
Portal was first included with the release of Half-Life 2's Orange Box. Now, each game from that pack is available as its own boxed title for gamers to pick and choose their favorites.